Which of the following is a known side effect of antipsychotic medications?

Weight gain is a well-documented side effect associated with many antipsychotic medications. These drugs can lead to metabolic changes, including increased appetite and alterations in how the body processes glucose and fat. As a result, individuals taking these medications may experience significant weight gain, which is particularly common with atypical antipsychotics.

In contrast, increased cognitive abilities, heightened alertness, and improved emotional regulation are not typical side effects of antipsychotic medications. While these medications can help stabilize mood and reduce symptoms such as hallucinations or delusions, they do not generally enhance cognitive function or alertness. Additionally, the sedating effects of many antipsychotics can actually contribute to drowsiness or lethargy, rather than heightened alertness. Therefore, weight gain stands out as the clear and recognized side effect in this context.